Remote control for rock drill



May 16, 1967 R. A. EDW'AFQDS REMOTE CONTROL FOR ROCK DRILL 4Sheets-Sheet 1 Filed Feb. 28, 1966 INVENTOR. R/CHARD A. EDWARDS BY 022wZTTOR/iW May 16, 1967 R. A. EDWARDS REMOTE CONTROL FOR ROCK DRILL 4Sheets-Sheet 2 Filed Feb. 28, 1966 May 16, 1967 R, A. EDWARDS REMOTECONTROL FOR ROCK DRILL 4 Sheets-Sheet 3 Filed Feb. 28, 1966 y 196'? R.A. EDWARDS 3,31%,725

REMOTE CONTROL FOR ROCK DRILL Filed Feb. 28, 1966 4 Sheets-Sheet 43,319,725 REMOTE CONTROL FOR ROCK DRILL Richard A. Edwards, Denver,Colo, assignor to Gardner- Denver Company, a corporation of DelawareFiled Feb. 28, 1965, Ser. No. 538,442 20 Claims. (Cl. 173-157) Thisapplication is a continuation-in-part of application Ser. No. 440,577filed Mar. 17, 1965 and now abandoned.

This invention relates to a remote control. for a drifter type rockdrill and, more particularly, to a remote and partially automaticcontrol for the drill and feed motor for a drifter type rock drill.

In certain rock drilling operations, such as the drilling of a tunnelface or mine drift, mobile multidrill drilling rigs are frequently used.Such drills may carry two or three drifter type drills mounted onmovable arms or booms whereby the drills are readily positioned byremote control relative to the work face. In the operation of the drillsthemselves, it has been necessary for the drill operator to closelyfollow the drilling of each hole so that he can shut off the drill motorand reverse the feed at the end of the drilling stroke, in order toprevent damage to the rock drill and/or its feed mounting. Therefore, touse the drills efficiently it has been necessary to provide an operatorfor each drill on a multidrill rig.

An object of this invention is to rovide a control for a drifter typerock drill which automatically controls a portion of the drilling cycleso that a single operator may operate efiiciently two or more rockdrills.

Another object of this invention is to provide a control for a driftertype rock drill which automatically feeds the drill toward. the work,shuts off or reduces the flow of air to the drill motor, and withdrawsthe drill from the work, and provides for manual control of the rate offeed toward the work.

A further object of this invention is to provide a remote control for adrifter type rock drill which provides for full manual control of thedrill motor and feed motor for starting a hole, and which provides forautomatic feed of the drill toward the work, shutoff or reduction of airflow to the drill motor, and withdrawal of the drill from the work.

A still further object of this invention is to provide a remote controlfor a drifter type rock drill which provides for automatic feed of thedrill to the work, drill motor shutoif, and withdrawal of the drill fromthe work; and which provides for manual operation of the drill motorduring withdrawal should conditions warrant.

In general, the invention is embodied in a main control valve andauxiliary valve for controlling, from a remote position, an air operatedrock drill which is mounted on a suitable feed mounting and which isdriven along the mounting by a reversible, air actuated feed motor. Themain control valve consists of a single valve member movable axially androtationally to control several functions. The valve member is normallyurged axially to a first limiting position in which air is eitherprevented from flowing to the drill motor or such flow is restricted,and in which air is directed to the feed motor to either retract thedrill or hold the drill in a retracted position. The valve member ismovable manually away from the first limiting position to direct air tothe drill motor for drilling and to direct air to the feed motor to feedthe drill along the mounting. Continued manual movement of the valvenited States Patent member, axially to a second limiting position,results in the admission of air to the valve chamber to hold the valvemember in this second limiting position. Manual rotation of the valvemember in this position regulates the rate of feed. From this point, thedrill cycle is automatic in that the feed motor will continue to feedthe drill until an auxiliary trip valve on the feed mounting is actuatedby the drill to vent the air from the valve chamber to effect return ofthe valve member to the first limiting position, to shut off or restrictair flow to the drill motor and to retract the drill.

The novel features of the invention, as well as additional objects andadvantages thereof, will be understood more fully from the followingdescription when read in connection with the accompanying drawings inwhich:

FIG. 1 is a diagrammatic showing of a drifter type rock drill andassociated feed mounting, of a control valve and trip valve according tothe present invention, and interconnecting air lines.

FIG. 2 is a sectional view of a trip valve which is attached to the feedmounting, including a showing of an actuator for the trip valve whichmay be attached to the rock drill.

FIG. 3 is a longitudinal sectional view of the control valve in positionto retract the rock drill.

FIG. 4 is a transverse section taken along the line 4-4 of FIG. 3,looking in the direction of the appended arrows.

FIG. 5 is a transverse section taken along the line 5-5 of FIG. 3,looking in the direction of the appended arrows.

FIG. 6 is a transverse section taken along the line 66 of FIG. 3,looking in the direction of the appended arrows.

FIG. 7 is a partial longitudinal section of the control valve, showingthe valve spool shifted axially and rotationally from the FIG. 3position.

FIG. 8 is a partial longitudinal section of the control valve, showingthe valve spool shifted axially further from the FIG. 3 position but inthe same rotational position.

FIG. 9 is a fragmentary longitudinal section taken along the line 9 ofFIG. 8, looking in the direction of the appended arrows.

FIG. 10 is a fragmentary longitudinal sectional view of a modified formof the valve shown in FIGS. 3 through 9, the position of the valvemember Within the valve chamber corresponding to that of FIG. 3.

FIG. 11 is a transverse section taken along the line 11-41 of FIG. 10,looking in the direction of the appended arrows.

FIG. 12 is a fragmentary longitudinal sectional view of the valve ofFIG. 10, corresponding to FIG. 7 in regard to the relative position ofthe valve member within the valve chamber.

FIG. 13 is a transverse section taken along the line 1313 of FIG. 12.

FIG. 14 is a transverse section, corresponding to that of FIG. 11 butshowing the valve member in a different rotational position.

Referring to FIG. 1, there is shown a conventional drifter type rockdrill 13 mounted on a conventional feed mounting 14, which consists of aguide shell having ways for slidably supporting the drill. A reversibleair motor 15, shown as a radial piston type air motor, is mounted at therearward end of the feed mounting 14 and drives a lead screw (not shown)which is rotatably supported within the feed mounting and extendssubstantially the full length of the feed mounting. This lead screw isin continuous engagement with a. fixed nut attached to the drill. Adrill rod centralizer 16 is mounted at the forward end of the feedmounting 14 for supporting a drill rod 17 carried in the drill 13.Rotation of the feed motor in one direction feeds the drill and drillrod toward the work face; and rotation of the feed motor in a reversedirection retracts the drill from the work face and withdraws the drillrod from the hole.

A main control valve 21 for controlling the operation of the drill motorand feed motor is diagrammatically shown in FIG. 1. This v-alve includesa single valve member having a T handle 22 which is grasped by theoperator for controlling the manually controlled portions of a drillingcycle. The control valve is connected to a source of compressed air by asupply conduit 23, is connected to the rock drill motor by a conduit 24,and is connected to the feed motor by a pair of conduits 25 and 26; allof the conduits preferably being in the form of flexible hoses.

When the valve is manually shifted to drilling position by the operator,the valve is held in this position by an air charge which is permittedto enter the valve chamber at one end of the valve. In order to returnthe valve to the retract position, the pressurized air must be ventedfrom this chamber; and for this purpose there is provided a trip valve30 which is mounted at a suitable position along the side of the feedmounting 14. This trip valve is connected to the main control valvechamber by means of a conduit 31, and serves to vent the one end of themain valve chamber when actuated. A trip valve actuator 32 consists ofan arm which is rigidly attached to the rock drill 13 to engage the tripvalve at the end of the drilling stroke. The position of the trip valve30 on the drill mounting is selected to provide the desired hole depth.

FIG. 2 is a detail view of a trip valve 30 which may be used in thepresent invention. This valve includes a housing 34 having a throughbore including a larger cylindrical portion 35 defining a valve chamberwhich terminates at one end in an annular shoulder 36, defining asmaller bore opening from that end. A valve member 37 is defined by acylindrical body which is slidably received within the larger bore 35,and a stem 38 which extends through the smaller bore in the valvehousing and projects therefrom. A spring retainer 39 is secured in thebore 35; and a spring 40, disposed between the spring retainer 39 andthe valve member 37, normally urges the valve member against theshoulder 36 so that the stem 38 projects from the housing. The body ofthe trip valve member 37 is provided with an annular groove which, whenmoved axially against the force of the spring 40, communicates inletport 41 with exhaust port 42. This vents the conduit 31, which isconnected to the inlet port, and the chamber of the main control valvewith which the conduit communicates. The trip valve 30 is mounted on thefeed mounting 14 in any desired manner; and FIG. 2 also shows therelation of the valve actuator 32 which is suitably mounted on the rockdrill 13.

The structure and operation of one form of main control valve 21 areillustrated in FIGS. 3 through 9. The main control valve includes agenerally cylindrical housing having a base flange 51 for the purpose ofmounting the valve housing on a suitable support, and which identifiesthe lower end of the valve for the purpose of the following description.The housing is provided with several projecting bosses having internallythreaded bores for the purpose of attaching certain air hoses to thehousing. The housing is provided with a cylindrical bore 52, defining avalve chamber, opening from the upper end thereof and terminating shortof the base. This chamber is dimensioned to accommodate a spool valve 53for axial and rotational movement. The spool valve includes lower,

center and upper lands '54, 56 and 58, respectively; the lands 54 and 56being separated by an annular groove 55, the lands 56 and 58 beingseparated by an annular groove 57. A stem 59, including a portion ofhexagonal cross section, extends upwardly from the upper land 58; andvalve handle 22 is rigidly secured to the upper end of the stem 59 bymeans of a suitable key and nut. The upper end of the valve housing isclosed by a cap 60 provided with an opening through which the stem 59passes.

In order to limit the rotation of the spool valve 53 within the valvehousing, a disclike index plate 63, best shown in FIGS. 3 and 4, isconfined within the cap 60 and rides on the top of the valve housing.This plate is provided with a hexagonal bore which receives thehexagonal stem of the spool valve 53, permitting axial movement of thespool valve relative to the plate and rotationally keying the plate tothe stem. Substantially one-half of the periphery of the index plate isof reduced diameter, defining a space to accommodate an index pin 64extending upwardly from a suitable bore in the housing wall, anddefining shoulders 65 spaced generally opposite each other to limit therotation of the index plate and the spool valve to 180". In FIG. 3, thespool valve is rotated to the counterclockwise limit, as viewed from thetop of the valve.

The normal axial position of the spool valve 53 is shown in FIG. 3; andthe valve is held in this position by a coil spring 68 which bearsagainst the upper shoulder of the valve land 58 and against the lowerface of the index plate 63. The spool valve is movable upwardly by anoperator raising the handle 22; and this upward movement is limited byengagement of a shoulder 69 on the valve stem with the lower face of theindex plate 63.

The supply connection for the control valve 21 is provided by boss 72(FIG. 4) having an internally threaded opening 73 in which the supplyconduit 23 is attached, and which opens to an internal annular groove 74in the valve chamber 52. In all positions of the spool valve, theannular groove 57 of the spool valve is in communication with thechamber groove 74 so that the annular groove 57 with the housing definesa supply chamber.

The drill motor conduit 24, which supplies air from the control valve tothe rock drill motor, is connected to the valve at boss 77 provided withan internally threaded passage communicating with internal annulargroove 78 in the valve chamber 52. The groove 78 defines a drill motorsupply port cooperating with the land 58 of the spool valve. It will beseen that the drill motor supply port 78 is closed by the land 58, inthe normal position of the valve, to prevent air flow to the drillmotor.

The feed motor hoses 25 and 26 are connected respectively at bosses '81and 82, the boss 81 having an internally threaded passage opening intothe valve chamber defining a feed port 83, and the boss 82 having aninternally threaded passage opening into the valve chamber defining aretract port 84. Referring to FIG. 3, it will be seen that the retractport 84 is in communication with the supply chamber 57 so that air isdirected to the feed motor 15 tending either to retract the drill 13 orto hold the drill in a retracted position against a suitable stopprovided on the feed mounting. The feed port 83, in this position of thevalve, defines an exhaust port for secondary exhaust from the motor 15.In the FIG. 3 position of the spool valve, the port 83 communicates withan exhaust chamber, which is defined by the annular groove 55 of thespool valve and the valve housing. As best shown in FIG. 5, an exhaustport 85 in the housing wall communicates the exhaust chamber '55 withatmosphere. The axial position of the exhaust port 85 is indicated bythe plane in FIG. 3 through which FIG. 5 is taken; and it will be seenthat the port 85 and the exhaust chamber '55 are in communication forall axial positions of the spool valve.

When the control valve is connected to air supply and the spool valve isin the FIG. 3 position and the drill 13 is fully retracted, there may besome leakage of air through the feed motor which exhausts from theexhaust port 85 resulting in objectionable noise. Accordingly, closuremeans is provided to close this exhaust port 85 when desired. Thisclosure means consists of a boss 86 on the control valve, best shown inFIGS. 3 and 5, which is defined by a radial projection into the valvegroove 55 and a downward extension of the cylindrical valve surfacedefined by the center land 56. When the spool valve 53 is rotated to theclockwise limiting position, and while the valve is in its lowermostposition as shown in FIG. 3, the boss '85 will cover the exhaust port 85as shown in phantom in FIG. 5. This boss is positioned so that it willnot interfere with other ports in the valve housing.

The operation of the control valve will now be described with referenceto other structural features of the valve which are best explained inrelation to the functions they perform.

In the drilling of many holes it is either necessary or desirable tocollar or start the hole, which consists of initially providing asurface which is normal to the direction of the feed of the rock bit andwhich will prevent the bit from tending to drift from the line of feed.This is accomplished by initial chipping of the rock face with the drillbit through close control of the feed and drill motor by the operator;and one of the features of the present control is the means by whichthis hole starting is controlled. The general position of the spoolvalve 53 for the hole starting operation is shown in FIG. 7. Referringparticularly to FIGS. 3 and 7, there is shown a hole starting feedpassage 91, in the spool valve 53, including a longitudinal portionwhich opens to the supply groove 57 and a radial portion defining anaxially elongated port 92 in the periphery of the lower land 54. Toposition the valve in the hole starting position, the valve is pulledmanually and rotated 90 clockwise from the FIG. 3 position, by theoperator, to align the port 92 with the fed port 83; and the valve mustbe held by the operator against the force of the spring 68 to maintainthis axial position. This axial shifting of the spool valve hascommunicated the retract port 84 with the exhaust chamber 55, to providefor operation of the feed motor in a direction to feed the rock drillforward. Now, through manual oscillation of the spool valve through afew degrees, the ports 92 and 83 may be intermittently communicated toprovide the desired control of feed.

Also, as seen in FIG. 7, the lower shoulder of the spool valve land 58lies generally in the plane of the lower wall of the annular groove 78which communicates with the drill motor conduit 24. A pair of V notches93 are provided in the cylindrical surface of the valve land 58,communicating with the lower shoulder, to provide for a very small flowof air from the supply chamber 57 to the annular groove 78 when desired,to provide for extremely throttled down operation of the drill motor.Slight upward movement of the spool valve will, of course, increase theflow of air to the drill motor; and slight reciprocating axial movementof the spool valve by the operator will provide very close throttlingcontrol of the drill motor. It will be seen, then, that the operator canclosely control the rock drill, for hole starting, through slight axialreciprocation of the valve for drill motor control and through slightrotary oscillation of the valve for feed motor control. Should it benecessary during this hole starting operation to retract the drill, itis only necessary to permit the spool valve to move axially downwarduntil the supply chamber 57 is communicated with the retract port 84.When the hole starting feed port 92 is in full communication with thefeed port 83, the maximum flow of feeding air permitted by the valve iseffected.

Once the hole has been started, the remainder of the drilling cycle iseffected by manually pulling the spool valve to its upper limitingposition, as shown in FIG. 8,

wherein the valve shoulder 69 engages the index plate 63 (FIG. 3). Inthis position, maximum flow of air is directed from the supply chamber57 through the drill motor supply hose 24 so that the rock drill 13operates at full throttle. If the rock drill 13 is provided with athrottle valve, this valve will be positioned and left at the fullthrottle position or some other position as indicated by the drillingconditions. Also, in this axial position of the spool valve 53 a feedthrottle groove 94, best shown in FIGS. 3, 6 and 8, is aligned axiallywith the feed port 83 of the valve chamber. The feed throttle groove 94is a V groove which is milled into the periphery of the lower spoolvalve land 54, extending angularly around the land and graduallydiminishing from a maximum section at one end of the groove to a minimumsection at the other end. The feed throttle groove 94 is communicatedwith the supply chamber 57 by means of a supply passage 95 consisting ofa longitudinal portion which is always open to the spool valve supplygroove 57, and a radial portion opening to the groove 94. The spoolvalve is shown rotated to the full throttle position in FIG. 8 and FIG.3, which is the counterclockwise limiting position of valve rotation asseen in FIG. 4. Rotation of the spool valve 90 clockwise from the fullthrottle position will reduce the feeding air from maximum to minimum;and further clockwise rotation will, of course, shut off the flow offeeding air.

When the spool valve is moved to the drilling position shown in FIG. 8,the lower end of the valve uncovers a restricted bleed port 96, which isin continuous communication with supply passage 73 by means of alongitudinal passage 97, as best shown in FIGS. 8 and 9. When this bleedport 96 is uncovered by the spool valve, the valve chamber 52 below thevalve is pressurized to hold the valve in the drilling position againstthe force of the spring 68. Therefore, when the operator pulls the spoolvalve manually to the drilling position, the valve will automaticallyhold this position until the holding air is released. Simultaneouslywith the axial movement of the valve to the drilling position, theexperienced operator will rotate the valve to select the desired feedrate; and the remainder of the drilling cycle will then proceedautomatically as will now be described.

At the lower end of the valve housing there is provided a passage 98which communicates with the lower end of the valve chamber 52 and with athreaded opening in the valve housing wall to which is attached the tripvalve conduit 31. The feeding of the drill toward the work, then, willcontinue until the stem 38 of the trip valve 30 is engaged by the tripvalve actuator 32, mounted on the rock drill, to vent the conduit 31and, therefore, the valve chamber beneath the spool valve 53. Thepressure in the chamber is reduced since air flow through the vent pathis greater than the flow of supply air through the restricted port 96.When this occurs, the spring 68 will immediately return the spool valveto its lower position shown in FIG. 3, closing the port 96. In thisposition, of course, the supply of air to the rock drill motor isimmediately shut off by the valve land 58, and the retract port 84 isagain communicated with the supply chamber 57 so that the feed motor 15retracts the drill from the work face and withdraws the drill rod 17from the hole which is now completed.

The control valve provides an alternative means to vent the chamberbelow the spool valve 53 for the purpose of returning the valve to thenormal position and to retract the rock drill at the will of theoperator. This provides a safety feature in the event of drill rodbreakage or other emergency situation. The alternative vent path isprovided by an axial passage 99 extending through the spool valve 53 toa point short of the stem end of the spool valve, and communicating witha passage 100 extending through one end of the T handle 22. The passage10!) opens to the end of the handle which defines a valve seat. This oneend of the handle is externally threaded to accommodate an axiallyelongated cap 101 which defines a relief valve closure member, theclosed end thereof sealing the opening from the passage 100. The endwall of the valve cap 101 is provided with ports 102 to vent thepassages 100 and 99 when the valve cap is unseated from the valve seat.This, of course, vents the valve chamber below the valve to etfectreturn of the valve to the FIG. 3 position. The surface of the valve cap101 may be knurled to facilitate its operation.

During the retraction of the drill and the withdrawal of the drill rodfrom the hole, the rod may become bound in the hole, requiring manualoperation of the drill to free it. This is readily accomplished throughmanual operation of the control valve to actuate the drill motor and toreverse the feed if necessary. During this operation, it may bedesirable to open the relief valve 101 so that the spool valve 53 willnot lock in the drilling position should the bleed port 96 be exposed.

FIGS. 10 through 14 illustrate a main control valve 21 which isgenerally similar to the above described main valve 21 in structure andoperation, but which is modified to provide restricted flow of air tothe drill motor while the drill is retracted on the feed mounting. Incertain drilling operations, this feature is desirable to reduce thepossibility of the drill bit becoming bound in the hole. In thedescription of this modified valve, the same reference numbers will beused where the parts are identical to the valve of FIGS. 3 through 9.

FIGS. 10 and 11 show the spool valve 53' in its normal axial position(corresponding to FIG. 3); the valve being urged to this position by thespring 68. These figures particularly show the drill motor supply portwhich is now defined by a partial annular groove 79 which communicateswith the passage in the boss 77 to which the drill motor conduit 24 isattached. The valve land 58', of the spool valve 53', is provided with alongitudinal groove 103 which communicates with the lower shoulder ofthe valve land 58' and extends upward for a distance sufiicient tocommunicate with the groove 79.

In FIGS. 10 and 11, the valve 53 is shown at its counterclockwiserotational limit; and it will be seen with particular reference to FIG.11 that the groove 103 will communicate with the groove 79 in rotationalositions of the valve between this counterclockwise limit and a positionapproaching 90 of clockwise rotation. This is the range of rotation ofthe valve for control of the rate of feed as described above; therefore,regardless of the rotational position of the spool valve 53' for thedesired feed rate,

when the valve is returned to its normal position reduced air flow willbe provided to the drill motor to operate the drill motor while thedrill bit is withdrawn from the hole.

FIGS. 12 and 13 illustrate the collaring position of the spool valve 53'(corresponding to FIG. 7), wherein the position of the spool valve 53'is manually controlled both axially and rotationally for control of thedrill motor and feed motor. It will be seen that the groove 103 is outof communication with groove 79, so that the control of restricted airflow to the drill motor is now provided by the single V notch 93cooperating with the partial annular groove 79.

When the above described modified control valve 21 is employed, thedrill motor will continue to hammer at the completion of each drillingcycle, since the groove 103 is in communication with the groove 79. Ifit is desired to stop the drill motor, the spool valve 53' is rotated toits clockwise limit, illustrated in FIG. 14, wherein the groove 103 isrotationally out of communication with the groove 79 thereby shuttingoff the flow of air to the drill motor. In this position, the valve boss86 is rotated to close the exhaust port 85 to prevent leakage of airthrough the feed motor, as described above.

A feature of the above described control is that an experienced operatormay, in one movement of the spool valve 53, start the drill cycle andset the feed rate, and

the remainder of the drill cycle will be completed automatically. Thatis, the operator will start the cycle by pulling on the handle 22 and,at the same time, rotating the handle to set the appropriate feed rate.Further, if the feed rate needs adjusting at any time during thedrilling, the handle 22 need only be rotated in one direction or theother to either increase or decrease the rate of feed.

Another feature of the control valve is the provision of full manualcontrol of both the drill motor and the feed motor for starting orcollaring the hole, should this be necessary.

Another feature of the control is the provision of the relief valve 101by means of which the operator may effect retraction of the rock drillat any time during the feeding portion of the drilling cycle. Stillanother feature of the control is that the operator may readily takeover manual operation of the control valve during the retract portion ofthe drilling cycle, to actuate the drill motor and reverse the feedmotor if this is necessary to free the drill rod, for example.

What is claimed is:

1. A control system for a rock drill and feed assembly including a drillfeed mounting, a rock drill supported on said mounting for reciprocatingmovement and having a fluid actuated drill motor, and a reversible fluidactuated feed motor for moving said drill along said mounting,characterized by:

a main valve comprising a housing, defining a valve chamber, and a valvemember disposed in said chamber; said housing having ports opening intosaid chamber including a supply port for communication with a source ofpressure fluid, a motor port for communication with said drill motor, afeed for port for communication with one side of said feed motor, and aretract port for communication with the other side of said feed motor;means projecting from said housing for manually actuating said valvemember;

means urging said valve member to a first position wherein said valvemember communicates said supply port with said retract port to effectretraction of said drill along said mounting; said valve member beingmovable to a second position wherein said valve member communicates saidsupply port with said motor port to actuate said drill motor, and withsaid feed port to effect feed of the drill along said housing;

means for directing pressure fluid to said valve chamber to hold saidvalve in said second position;

an auxiliary valve communicating with said main valve chamber andmounted to be actuated in response to predetermined feed movement ofsaid drill along said mounting; said auxiliary valve, when actuated,venting said main valve chamber to effect the shifting of said mainvalve member to said first position.

2. The invention set forth in claim 1 wherein said main valve member, insaid first position,

provides restricted communication between said supply port and saidmotor port to provide for throttled down operation of said drill motor.

3. The invention set forth in claim 1 wherein said main valve member isa spool valve movable axially between said first and second positions;and wherein said means for directing pressure fluid to said valvechamber is a restricted port in said chamber wall communicating withsaid supply port and position to be exposed by said spool valve in saidsecond position.

4. The invention set forth in claim 3 wherein said spool valve has portmeans axially aligned with said housing feed port in said secondposition, and coacting with said housing feed port in response tolimited oscillation of said spool valve to regulate the flow of pressurefluid to said feed motor.

5. The invention set forth in claim 3 wherein said spool valve has arecess continuously com- 9. municating with said supply port anddefining a supply chamber;

said spool valve having an angularly extending feed port communicatingwith said supply chamber; said valve It said valve member occupying afirst position wherein said supply chamber is communicated with saidretract port; and said valve member occupying a second position whereinsaid supply chamber is comfeed port being axially aligned with saidhousing feed municated with said motor port and wherein said port insaid second position of said valve, and said throttling port iscommunicated with said feed port. feed ports coacting in response torotation of said 12. The invention set forth in claim 11 spool valve toregulate the flow of pressure fluid to wherein said valve member, insaid first position, prosaid feed motor. vides restricted communicationbetween said supply 6. The invention set forth in claim3 1O chamber andsaid motor port to provide for rewherein said spool valve has a recesscontinuously comstricted fluid flow through the motor port to a drillmunicating with said supply port and defining a motor. supply chamber;said supply chamber being in direct 13. The invention set forth in claim11 and full communication with said motor port in said wherein saidvalve member is a spool valve movable second position of said spoolvalve, and said supply 15 axially between said first and secondpositions; wherechamber being axially displaced from said motor in saidmeans for actuating said valve member is a port in said first positionof said spool valve. stem extending axially from said spool valve; 7.The invention set forth in claim 6 and wherein said throttling port isaxially aligned wtih wherein said spool valve, in said first position,prosaid feed port in said second position, said throttling vides arestricted flow path for pressure fluid between port coacting with saidfeed port in response to limsaid supply chamber and said motor port, toeffect ited oscillation of said spool valve to regulate the operation ofsaid drill motor at reduced throttle. flow of pressure fluid throughsaid feed port. 8. The invention set forth in claim 3 14. The inventionset forth in claim 13 wherein a manual control handle is rigidlyattached to wherein said throttling port comprises a partial annuone endof said spool valve, defining said means prolar groove of varyingsection. jecting from said housing; 15. The invention set forth in claim13 including: said spool valve and handle having a passage opening meansurging said valve member to said first axial from said handle andopening from the other end position; said valve member being movable tosaid of said spool valve to communicate with said valve second axialposition against the force of said urgchamber; and manually operatedclosure means on ing means; said handle for selectively opening saidpassage to means for holding said valve member in said second vent saidValve chamber, said closure means defining axial position; and means forreleasing said valve an alternative valve means for venting said valveholding means to effect the shifting of said valve chamber to effect theshifting of said spool valve to member to said first axial position.said first position. 16. The invention set forth in claim 13 including:9. The invention set forth in claim 1 spring means urging said valvemember to said first wherein said valve member is movable to anintermediaxial position;

ate position to provide manually controlled restricted a restricted portin said housing opening to said valve communication of said supply portwith said motor chamber adjacent one end thereof and communicatport andwith said feed port. ing with said supply port; said restricted portbeing 10. The invention set forth in claim 3 closed by said valve memberin said first axial posiwherein said spool valve is provided with aradially tion, and being exposed by said valve member in opening feedport communicating with said supply said second axial position to effectthe pressurizachamber; tion of said one end of said valve chamber tohold said spool valve being movable to an intermediate axial aid valvemember in said second position agianst position wherein said supplychamber begins to comthe force of said spring means; Inunicate With SaidP P and wherein a Valve and means for venting said one end of saidchamber feed port is axially aligned with said housing fe to effect theshifting of said valve member to said port; said spool valve, in saidintermediate position, first position by Said spring means providing formanual regulation of fluid flow to said drill motor and to said feedmotor through slight manual reciprocation and oscillation of said spoolvalve, respectively.

11. A remote control valve for use with a drifter type 17. The inventionset forth in claim 16 including:

a control handle secured to said valve member stern;

said venting means comprising passage means in said valve member andsaid handle, opening to said one end of said chamber and opening fromsaid handle;

rock drill mounted on a feed mounting for reciprocating movement by areversible feed motor, said control valve comprising:

and closure means on said handle for selectively opening said passage.

a housing defining a valve chamber; a valve member disposed in saidchamber; means projecting from 18. The invention set forth in claim 13.wherein said supply chamber is in direct and full comsaid housing f rmanually actuating i valve munication with said motor port in saidsecond posib tion of said valve member, and wherein said supply saidhousing providing individual port means opening chamber is axiallydisplaced from said motor port into said valve chamber defining a supplyport for in said first position of said valve member.

communication with a source of pressure fluid, a 19. The invention setforth in claim 18 motor port for communication with a drill motor, awherein said valve member, in said first position, profeed port forcommunication with one side of a revides a restricted flow path forpressure fluid between versible feed motor to effect feed of a drill,and a said supply chamber and said motor port, to effect retract portfor communication with the other side operation of said drill motor atreduced throttle.

of the reversible feed motor to effect retraction of 20. The inventionset forth in claim 13 the drill; wherein said valve member is providedwith a radially said valve member having a recess defining a supplyopening feed port communicating with said supply chamber in continuouscommunication with said supchamber;

ply port, and having a throttling port communicating said valve memberbeing movable to an intermediate with said recess; axial position,between said first and second positions,

wherein said supply chamber begins to communicate with said motor portand wherein said valve feed port is axially aligned with said housingfeed port; said valve member, in said intermediate position, providingfor manual regulation of fluid flow through said motor port and throughsaid housing feed port through slight manual reciprocation andoscillation of said spool valve, respectively.

References Cited by the Examiner UNITED STATES PATENTS Stage 173-19Weaver 137-62517 Sindelar 173-12 Jonsson 17319 Clapp et a1 173--159 FREDC. MATTERN, ]R., Primary Examiner. L. P. KESSLER, Assistant Examiner.

1. A CONTROL SYSTEM FOR A ROCK DRILL AND FEED ASSEMBLY INCLUDING A DRILLFEED MOUNTING, A ROCK DRILL SUPPORTED ON SAID MOUNTING FOR RECIPROCATINGMOVEMENT AND HAVING A FLUID ACTUATED DRILL MOTOR, AND A REVERSIBLE FLUIDACTUATED FEED MOTOR FOR MOVING SAID DRILL ALONG SAID MOUNTING,CHARACTERIZED BY: A MAIN VALVE COMPRISING A HOUSING, DEFINING A VALVECHAMBER, AND A VALVE MEMBER DISPOSED IN SAID CHAMBER; SAID HOUSINGHAVING PORTS OPENING INTO SAID CHAMBER INCLUDING A SUPPLY PORT FORCOMMUNICATION WITH A SOURCE OF PRESSURE FLUID, A MOTOR PORT FORCOMMUNICATION WITH SAID DRILL MOTOR, A FEED FOR PORT FOR COMMUNICATIONWITH ONE SIDE OF SAID FEED MOTOR, AND A RETRACT PORT FOR COMMUNICATIONWITH THE OTHER SIDE OF SAID FEED MOTOR; MEANS PROJECTING FROM SAIDHOUSING FOR MANUALLY ACTUATING SAID VALVE MEMBER; MEANS URGING SAIDVALVE MEMBER TO A FIRST POSITION WHEREIN SAID VALVE MEMBER COMMUNICATESSAID SUPPLY PORT WITH SAID RETRACT PORT TO EFFECT RETRACTION OF SAIDDRILL ALONG SAID MOUNTING; SAID VALVE MEMBER BEING MOVABLE TO A SECONDPOSITION WHEREIN SAID VALVE MEMBER COMMUNICATES SAID SUPPLY PORT WITHSAID MOTOR PORT TO ACTUATE SAID DRILL MOTOR, AND WITH SAID FEED PORT TOEFFECT FEED OF THE DRILL ALONG SAID HOUSING; MEANS FOR DIRECTINGPRESSURE FLUID TO SAID VALVE CHAMBER TO HOLD SAID VALVE IN SAID SECONDPOSITION; AN AUXILIARY VALVE COMMUNICATING WITH SAID MAIN VALVE CHAMBERAND MOUNTED TO BE ACTUATED IN RESPONSE TO PREDETERMINED FEED MOVEMENT OFSAID DRILL ALONG SAID MOUNTING; SAID AUXILIARY VALVE, WHEN ACTUATED,VENTING SAID MAIN VALVE CHAMBER TO EFFECT THE SHIFTING OF SAID MAINVALVE MEMBER TO SAID FIRST POSITION.